Families and friends are waiting to hear news about loved ones after the helicopter crash in Glasgow where eight people died.

A "very sensitive and complex" police rescue operation to find potential survivors is taking place at the Clutha pub - where the aircraft came through the roof.

Officers have described it as a "complicated and dangerous" environment.

One worried relative at the scene of the crash, Alice Healy, told Sky News she had not heard from her cousin who had been inside the pub when the helicopter hit.

Another, John McGarrigle, 38, said that he had been told by someone inside the pub that his 59-year-old father, also called John, had been sitting at precisely the spot the aircraft had come down and that he had been killed, but that authorities had not been able to confirm this.

John McGarrigle says he is sure his father has been killed in the crash

Three crew members - two police officers and a civilian pilot - died in the aircraft and five other people lost their lives inside the pub.

Flags across Scotland are flying at half-mast following the tragedy as the Queen says her "thought and prayers" are with those affected.

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Gallery: Helicopter Smashes Into Roof Of Pub

A police helicopter crashed into the roof of the Clutha bar on the banks of the Clyde in Glasgow on Friday night.

First Minister Alex Salmond - who called the crash a "black day for Glasgow and for Scotland" - ordered Scottish saltire and lion rampant flags outside Scottish Government and historic buildings to fly at half-mast.

St Andrew's Day events in the city were also scrapped and a minute's silence has been held at many football grounds.

With 14 people still seriously injured in hospital, players and fans at Scottish Cup fourth-round matches showed their solidarity and fell silent before kick-off.